WASHINGTON (CNN) - Two days from now, we’ll shift our sights from Iowa to another deadlocked contest in an icy state – the New Hampshire primary, where voters weigh in January 8. And just as Iowa’s outcome seemed to get less, not more, certain as the caucuses drew closer, the presidential race in New Hampshire is now tighter than ever, according to a new CNN/WMUR survey.

The poll, conducted by the University of New Hampshire Survey Center, finds Republicans John McCain and Mitt Romney tied for first place, with 29 percent each – a huge comeback for the Arizona senator, who was written off by many pundits after his campaign imploded earlier in the year. Six months ago, he placed fourth in the same poll, with support just barely in double digits.

Rounding out the third and fourth spot in the new poll are Rudy Giuliani and Mike Huckabee, who receive 12 and 10 percent support, respectively, from GOP primary voters.

The Democratic primary race is also neck-and-neck: Hillary Clinton has a statistically insignificant 4-point edge over Barack Obama, 34 percent to 30 percent. John Edwards is in third place with 17 percent.

But roughly one out of every four voters in either party say they won’t make a decision until Election Day. And since Hawkeye State returns often help shift the tone in New Hampshire, the impact of tomorrow’s Iowa results may be felt at Granite State polls on Tuesday.

So here’s Iowa by the numbers: roughly $40 million in television ads, thousands of volunteer man-hours, more than two years of campaigning – and one more day.

(And if you’re on the campaign trail in the Hawkeye State today, here are a few more important numbers to keep in mind, thanks to CNN’s Weather Team: the high will be around 10 degrees in eastern Iowa and 20 degrees in the western part of the state during the day, with a wind chill advisory in effect for northern areas through early Wednesday morning. At night, the low will range from a bone-chilling 5 below in the eastern part of the state, to the relatively balmy 10 above further west.)